Bluetooth is a short range wireless networking system operating in the ISM 2.4 GHz band. The development of Bluetooth has required designers of disparate electronic devices to include rf circuitry for the first time and, in the case of mobile phones, additional rf circuitry. This of course can lead to undesirable increases in the size of devices to accommodate the electronics and the antenna or antennas required.
PCB antennas are disclosed in DE-U-29701 589, GB-A-2237451 and U.S. Pat. No. 5,898,404. However, in each of these documents the elements are formed from single layers of conductor.